Daddy Cool's singer and rock veteran Ross Wilson tweeted the news announcing his bandmate lost his battle with cancer on Tuesday.
"Sad to tell you that my friend Ross Hannaford has passed away," Wilson posted on his Twitter page, Ross Wilson Music.
Hannaford was the lead guitarist for Daddy Cool which formed in Melbourne in 1970.
The band's debut single Eagle Rock topped the charts in 1971 and is an iconic Australian rock song.
Hannaford was inducted into the ARIA Hall Of Fame in 2006 as one of the members of Daddy Cool.
ARIA posted a photo of Hannaford on its Twitter page with the caption: "ARIA extends condolences to the family, friends and fans of Daddy Cool guitarist Ross Hannaford who has passed at 65."
Hannaford's career spanned 50 years beginning in the mid 1960s at age 16 with the Pink Finks.
He recorded and played with a number of acts including Party Machine, Sons of the Vegetal Mother, The Black Sorrows, Goanna, Ian Moss, Billy T and Dianna Kiss.